In a stunning move, the Eagles have named offensive line coach Juan Castillo to be the team's next defensive coordinator, a league source told The Inquirer.

Howard Mudd, considered one of the best offensive line coaches in the game, will replace Castillo.

The team later made the moves official.

Castillo has been the Eagles' offensive line coach for more than 15 years. He was, however, once a linebackers in the USFL. The Eagles are known for promoting within, but the move is a shocker and will be questioned by many.

Castillo replaces Sean McDermott, who was fired almost three weeks ago after two seasons at the helm. McDermott worked his way up through the organization and was a defensive coach for over a decade.

The 51-year-old Castillo has been an Eagles offensive assistant since 1995 when he was a part of Ray Rhodes' staff. He became the team's tight ends coach two season later and then offensive line coach a year later.

Castillo was one of the few leftovers from the Rhodes regime that new head coach Andy Reid kept on staff when he was hired in 1999. Castillo has long been hailed as one of the best line coaches in the league although that unit has struggled in the last two seasons.

He does have some experience as a defensive coach. He was the defensive line/linebackers coach at Texas A&M-University Kingsville in the early 1980s and then the defensive coordinator at Kingsville High School in the late 1980s. In between, he was a linebacker in the USFL.